X-ray free-electron lasers (XFELs), that now provide millijoule pulses of hard x-rays with sub-100 fs duration, pave the way towards direct atomic resolution diffractive imaging of single isolated molecules and particles. However, these experiments require the controlled delivery of identical species into the sub-µm x-ray focal spot in vacuo.
Here I will introduce the COMOTION project, which aims to provide exactly that - well controlled and intact biological samples in the gas-phase, suitable for use in XFEL experiments. I will describe how we can gently vaporise biological molecules - from small amino acids to entire virus particles, and cool them to cryogenic temperatures. We can further control certain degrees of freedom for these samples, such as spatially separating conformers of dipeptide molecules, producing extremely collimated (and hence dense) nanoparticle beams, or aligning and orienting molecules in space. Produced samples are not only applicable to the next generation of single-particle diffractive imaging at XFELs, but are of interest to a wide range of experiments across physics, chemistry and biology alike.
Dr Daniel A. Horke
Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany.